Patent Application
20240360934
The present disclosure relates to composite joints and more particularly to self-locking composite-composite joints for tubular components.
For weight and performance benefits, aircraft water collectors are often fabricated with composite shells as separate tubular-type segments with follow-up joining. The composite shells are typically polymer-matrix composites with or without fiber reinforcement. The fiber can be usually short, randomly distributed fiber segments or, in some cases, complimented by continuous long fibers. The segments can have non-uniform diameters along their axes for efficient installation of internal components. Their axial cross-sections can also have linear or curved profiles to optimize system-level performance of water collectors. The most typical load conditions are internal pressure, generating both radial expansion and axial tension. Thus, joining solutions between separate segments should be strong enough to perform such local load transfers and, especially, the axial tension.
In conventional solutions for such joints, the load transfer is based on adhesion between connected segments and radially-positioned metallic fasteners. However, radial fasteners through thickness of composite shells can cause significant stress concentrations in the composite parts, with corresponding increased risks of their damage. In addition, the fasteners can, in some cases, increase risks of leakage and/or generate additional challenges with smoothness of internal surfaces, needed for successful performance of internal flow.
The conventional techniques have been considered satisfactory for their intended purpose. However, there is an ever present need for improved designs and methods of fabrication/installation for joints between pipe-type composite segments, providing sufficient resistance to both radial and axial expansions. This disclosure provides a solution for this need.
In accordance with at least one aspect of this disclosure, a fastener free joining system, includes, a first tubular shell-type component having a first plurality of teeth defined in a first free end, each tooth extending along a respective tooth axis oblique to an axis of the first component by an angle α. The first plurality of teeth is configured to engage with a plurality of complimentary teeth defined in a second free end of a second tubular shell-type component, such that, when engaged, the first plurality of teeth is configured to remain engaged with the plurality of complimentary teeth under axial load.
In embodiments, the first plurality of teeth is configured to remain engaged with the plurality of complimentary teeth under purely axial tension (e.g., having no torsional component). In embodiments, the first plurality of teeth can be configured to remain engaged with the plurality of complimentary teeth under axial tension without a fastener or other adhesion means therebetween.
Each tooth of the first plurality of teeth can be oblique relative to the axis by an angle α to prevent disengagement of the first component from the second component under axial tension. In embodiments, the angle α between the respective tooth axis and the first component axis can be constant along a length of a respective tooth. In embodiments, the angle α between the respective tooth axis and the first component axis can be variable along a length of a respective tooth.
In embodiments, a geometry of each tooth can be uniform along a length of the tooth from a base of the tooth to a tip of the tooth (e.g., along the respective tooth axis). In embodiments, the geometry of each tooth can be non-uniform along a length of the tooth from a base of the tooth to a tip of the tooth (e.g., along the respective tooth axis). In certain embodiments, each tooth of the first plurality of teeth can be defined through an entire annular thickness of the first component. In certain embodiments, each tooth of the first plurality of teeth can be defined through only a portion of an annular thickness of the first component. In certain embodiments, the portion of the annular thickness of the first component can be an internal portion defined between an inner surface and an outer surface of the first component, or can be an outer portion (e.g., an upper or lower portion).
In accordance with at least one aspect of this disclosure, a system (e.g., a multi-pipe segment system) can employ the fastener free joining system as described herein. In certain embodiments, the system can be a water collector (e.g., for an aircraft). The system can include a first tubular component defining a first axis and having a first plurality of teeth defined in a first free end thereof, each tooth extending along a respective tooth axis angled oblique to the first axis by an angle α. The system can include a second tubular component defining a second axis and having a second plurality of teeth defined in a second free end thereof each tooth extending along a respective tooth axis angled oblique to the second axis by the angle α. The second plurality of teeth can be complimentary to the first plurality of teeth and configured to engage with the first plurality of teeth to join the first component and the second components coaxially to form a joint therebetween. When engaged, the first component and second components can be configured to remain engaged at the joint when the first and second component are under axial load.
In certain embodiments, the first component and/or the second component can be of a polymer or a fiber-reinforced polymer. In certain embodiments, the fiber reinforced polymer can be reinforced with any combination of short or continuous fibers. In certain embodiments, the contact surfaces between the first component and the second component can be joined by one or more of: adhesive or glue, co-curing (e.g., for thermoset polymers), or welding (e.g., for thermoplastic polymers).
In certain embodiments, the system can include a ring configured to interface with an outer surface of a portion of the first tubular component and an outer surface of a portion of the second tubular component at a location over the joint to provide contact pressure to the joint. In certain embodiments, at least the first component can include a first wedge portion (e.g., of linearly non-uniform diameter) defined in the outer surface and along a circumferential direction. In such embodiments, the ring can include a generally complimentary inner diameter profile configured to interface with the first wedge portion to provide contact pressure to the joint. In embodiments, the second component can also include a second wedge portion (e.g., of linearly non-uniform diameter) defined in the outer surface and along a circumferential direction, axially aligned with the first wedge portion of the first component to form a contiguous wedge structure. In such embodiments, the ring can include a generally complimentary inner diameter profile configured to interface with the contiguous wedge structure to provide contact pressure to the joint.
In certain embodiments, the first component can include a first wedge portion defined in the outer surface thereof and the second component can include a second wedge portion defined in the outer surface thereof facing opposite the first wedge portion to form a peak therebetween. In certain such embodiments, the ring can include a first ring portion having a complimentary inner diameter profile configured to interface with the first wedge portion and a second ring portion having a complimentary inner diameter configured to interface with the second wedge portion, the first and second ring portions configured to meet at the peak to provide contact pressure to the joint.
In accordance with at least one aspect of this disclosure, a method can include forming a first tubular component defining a first axis and having a first plurality of teeth defined in a first free end thereof, each tooth extending along a respective tooth axis angled oblique to the first axis by an angle α, forming a second tubular component defining a second axis and having a second plurality of teeth defined in a second free end thereof, each tooth extending along a respective tooth axis angled oblique to the second axis by the angle α, the second plurality of teeth complimentary to the first plurality of teeth, and engaging the first plurality of teeth with the second plurality of teeth to join the first component and the second component coaxially to form a joint therebetween such that, when engaged, the first component and second component remain engaged under axial tension.
In embodiments, the method can include, installing a ring on an outer surface of a portion of the first component and the second component at the joint to provide contact pressure to the joint. In embodiments, installing the ring can include thermally shrinking the first and second components before installing the ring and allowing the first and second components to thermally expand into the ring such that the ring provides contact pressure to the joint. In embodiments, installing the ring can include installing the ring on a wedge structure defined on at least one of the first and or second component. In certain embodiments, installing the ring can include installing a first ring portion over a first wedge structure defined in the first component and a second ring portion over a second wedge structure defined on the second component.
These and other features of the systems and methods of the subject disclosure will become more readily apparent to those skilled in the art from the following detailed description taken in conjunction with the drawings.
So that those skilled in the art to which the subject disclosure appertains will readily understand how to make and use the devices and methods of the subject disclosure without undue experimentation, other embodiments thereof will be described in detail herein below with reference to certain figures, wherein:
Reference will now be made to the drawings wherein like reference numerals identify similar structural features or aspects of the subject disclosure. For purposes of explanation and illustration, and not limitation, an illustrative view of an embodiment of a system in accordance with the disclosure is shown in
With reference to
In embodiments, the first plurality of teeth 104 are configured to remain engaged with the plurality of complimentary teeth 108 under purely axial load (e.g., having no rotational component) such that the first and the second components 102, 112 do not come apart when, for example, axial tension alone is applied. In embodiments, the first plurality of teeth 104 can be configured to remain engaged with the plurality of complimentary teeth 108 under axial tension and without a fastener or other adhesion means therebetween,
Each tooth 104/108 can define a base 104a/108a and a tip 104b/108b. Each tooth 104/108 can be oblique relative to the axis A1/A2 by a non-zero angle α to prevent disengagement of the first component 102 from the second component 112 under axial tension. As shown, angling the tooth 104/108 relative to the axis A/A2 can mean the tip 104a/108a of each tooth 104/108 is clocked circumferentially relative to the base 104b/108b of the tooth 104/108. In embodiments, the angle α can be constant along a length of a respective tooth 104/108, e.g., from the base to the tip as shown in
Although embodiments shown in
With reference now to
With reference now to
When engaged (e.g., installed in the system 200 to form at least one joint 224), the first component 202 and second component 212, are configured to remain engaged at the joint 224 when the first and second component 202, 212 are under axial load. In the example of a water collector 222, a fluid, e.g., air and/or water, may be flowing through the first and the second components 202, 212 and exerting a radial pressure on the joint 224, as shown in
In certain embodiments, an external reinforcing ring 326 can be included to provide a contact pressure to the joint 224, wherein the external ring does not extend into the pipe segment formed by the first and second tubular components. Certain embodiments can include an adhesion means to adhere the ring to the first and second components 202, 212, however, the system 100/200 and ring 326 are configured and adapted for use without any adhesion means or fasteners (e.g., radial fasteners) to join the first and second components 202, 212 together.
In embodiments, the ring 326 can be configured to interface with the outer surface 218 of a portion of the first component 202 and the outer surface 220 of a portion of the second component 212 at a location 228 over the joint 224, for example as shown in
In certain embodiments, for example as shown in
In certain embodiments, for example as shown in
In accordance with at least one aspect of this disclosure, a method (e.g., a method of joining the first and second components 102, 112/202, 212) can include forming a first component 102/202 defining a first axis A1 and having a first plurality of teeth 104 defined in a first free end thereof, the teeth 104 oriented oblique to the first axis by an angle α. The method can include forming a second component 112/212 defining a second axis A2 and having a second plurality of teeth 108 defined in a second free end thereof, the teeth 108 oriented oblique to the second axis by the angle α, and the second plurality of teeth 108 being complimentary to the first plurality of teeth 104. The method can further include engaging the first plurality of teeth with the second plurality of teeth to join the first component and the second component coaxially, along axes A1/A2 to form a joint 224 therebetween such that, when engaged, the first component and second component remain engaged under axial tension. Engaging the teeth can include pushing the components together axially while also twisting the components relative to one another.
In embodiments, the method can include, installing a ring 326 on an outer surface of a portion of the first component and the second component at the joint to provide contact pressure to the joint 224 (e.g., as shown in
Embodiments allow for fastener-free joints between pipe-type composite segments, providing sufficient resistance to both radial and axial expansions expected in typical implementations of water collectors, for example. As described herein, a joining system can include a connection of two composite pipe ends is designed with interconnected teeth, oriented with non-zero angle α with respect to axial position z (e.g., as shown in
In certain embodiments, the interconnected teeth can contact each other through the entire annular thickness (e.g.,
In embodiments, all or partial contact areas between connected pipe ends can have a) mutual adhesion, b) be welded in case of thermoplastic composites, or c) co-cured in case of thermoset composites, but all without requiring a fastener to extend between overlapping portions of the pipes at the joint. In certain embodiments, an external ring can be added to a) apply additional pressure in the radial direction and/or b) increase adhesive/welded contact areas (e.g., as shown in
In embodiments, the materials of the composite pipes and the external ring can be or include polymer-matrix fiber-reinforced composites with either short fiber reinforcement or/and long continuous fibers. Uni-directional continuous reinforcement in the hoop direction can be especially beneficial for the rings shown in
In embodiments, methods of making the components 102/202, 112/212, upon connection, opposite pipe ends are “twisted” relative to each other upon installation. In order to actually engage the respective teeth of the components, the components are moved both axially and rotationally to fit into place. This prevents disengagement of the components from one another when under axial load, where no twisting motion is applied. The larger the angle α is the more difficult it is to separate the components under axial load.
In embodiments that including the additional ring, upon installation of external ring(s) with sloped contact surface, the ring(s) can be forced in the axial direction until connection with complimentary sloped surface(s) of external surfaces of the pipes (e.g.,
In embodiments, installing the first component and the second component together and the ring, if applicable, corresponding contact surfaces can be additionally strengthened. Methods to make the contacts stronger can include application of adhesion or glue, co-solidifying in case of thermoplastics, different types of welding applicable for thermoplastics and co-curing for thermosets, depending on the respective materials used to form the components and the rings.
In embodiments having a flat-shaped ring (e.g.,
In other embodiments for a flat-shaped ring (
Embodiments described herein include a self-locking design(s) which can make water collectors more reliable, since because embodiments reduce the need for adhesion, which has a higher sensitivity to environmental conditions and can degrade over time.
Embodiments include a fastener-free composite/composite joints for composite water collectors which can following benefits: a) reduced risk of damage due to eliminated stress concentrations around fasteners; b) reduced risk of leakage; and c) enhanced smoothness of internal surface for improved flow.
While embodiments of the fastener free joining system are described herein with respect to use in a water collector, one having ordinary skill in the art having the benefit of this disclosure would readily appreciate that embodiments of the fastener free joining system can be applied to any suitable structure where composite pipe-type components are to be joined for reliable load transfer.
Those having ordinary skill in the art understand that any numerical values disclosed herein can be exact values or can be values within a range. Further, any terms of approximation (e.g., “about”, “approximately”, “around”) used in this disclosure can mean the stated value within a range. For example, in certain embodiments, the range can be within (plus or minus) 20%, or within 10%, or within 5%, or within 2%, or within any other suitable percentage or number as appreciated by those having ordinary skill in the art (e.g., for known tolerance limits or error ranges).
The articles “a”, “an”, and “the” as used herein and in the appended claims are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article unless the context clearly indicates otherwise. By way of example, “an element” means one element or more than one element.
The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and/or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and/or B”, when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.
As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of” or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e., “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.”
Any suitable combination(s) of any disclosed embodiments and/or any suitable portion(s) thereof are contemplated herein as appreciated by those having ordinary skill in the art in view of this disclosure.
The embodiments of the present disclosure, as described above and shown in the drawings, provide for improvement in the art to which they pertain. While the apparatus and methods of the subject disclosure have been shown and described, those skilled in the art will readily appreciate that changes and/or modifications may be made thereto without departing from the scope of the subject disclosure.
